lighting and watts/gal

[Soeman]

i'm sure there's been more than one post on this, so if someone knows of a good thread to link that'd be great.

It just seems to me that the watts per gallon rule is a bit misleading... i can replace my 30W incadescent with a 30W spiral fluorescent... going by the W/g rule, I havent made any gains, but the tank sure is a whole lot brighter. Obviously the light spectrum is not the same, and depends if I'm getting cool whites or kitchen/bathroom (which one is better?). In terms for aquatic plants, has anyone figured out new guidlines (or equivilancies) based on different light technologies?

[dan2x38]

Cool whites & Kitchen are something like 2400k light temp... a good light temp. for plants should be close to 6500k.

[kennyman]

watts is a measurement of power consumption. Not light. An incandescent lamp uses around 90% of the energy (watts) to make heat. It is very inefficient. Fluorescent lamps use more of the energy to make light and less for heat.

so you get a lot more light from 30 W of fluorescent than you do incandescent. Something around 300% more when you concider a 30W fluorescent makes as much light as a 100W incandescent. This is all before spectrum is factored in.

If lamps have the same spectrum you can use the lumen rating to see the difference. But lumens are cri dependant I believe so with actincis and such you cant get a fair comparison.